(a) Field of the Disclosure
The present disclosure relates generally to a microphone and a manufacturing method thereof, and more particularly, to a microphone that realizes a direction characteristic by applying a sound delay filter, and a manufacturing method thereof.
(b) Description of the Related Art
In general, a microphone is known as a device that converts sound to an electric signal. The microphone can be applied to mobile communication devices such as a smart phone or other various communication devices such as an earphone, a hearing aid, and the like. Such implementations require a microphone with good sound performance, reliability, and operability.
Microphones are classified into a non-directional (omnidirectional) and a directional. The directional microphone is a microphone where sensitivity is changed according to a direction of an incident sound wave, and is classified into single directional microphones and bi-directional microphones. For example, the directional microphone is often used for recording in a small room or for picking up only desired sound in a room with reverberation.
A micro-electro-mechanical system (MEMS)-based capacitive microphone (hereinafter referred as a MEMS microphone) has excellent sound performance, reliability, and operability compared to a conventional electret condenser microphone. When such microphone is employed in a vehicle, the microphone must be robust to variation in the noise environment because the vehicle environment is one where a sound source is distant and a noise is variably generated. However, in order to realize the MEMS-based directional microphone, two or more MEMS microphones are required, thereby increasing cost.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore it may contain information that does not form the related art that is already known in this country to a person of ordinary skill in the art.